website: Adding FAQ page. Fixes #363.

website/source/docs/faq.html.markdown

@@ -0,0 +1,18 @@
+---
+layout: "docs"
+page_title: "Frequently Asked Questions"
+sidebar_current: "docs-faq"
+---
+
+# Frequently Asked Questions
+
+## Q: Why is virtual memory usage high?
+
+Consul makes use of [LMDB](http://symas.com/mdb/) internally for various data
+storage purposes. LMDB relies on using memory-mapping, a technique in which
+a sparse file is represented as a contiguous range of memory. Consul configures
+high limits for these file sizes, and as a result relies on a large chunks of
+virtual memory to be allocated. However, in practice the limits are much larger
+than any realistic deployment of Consul would ever use, and the resident memory or
+physical memory used is much lower.
+

website/source/layouts/docs.erb

@@ -185,6 +185,9 @@
                     </li>
                 </ul>
 
+				<li<%= sidebar_current("docs-faq") %>>
+				<a href="/docs/faq.html">Frequently Asked Questions</a>
+				</li>
 			</ul>
 		</div>
 	<% end %>